diff --git a/chrome/content/zotero/xpcom/citeproc.js b/chrome/content/zotero/xpcom/citeproc.js
index 756c8569c..82d331da4 100644
--- a/chrome/content/zotero/xpcom/citeproc.js
+++ b/chrome/content/zotero/xpcom/citeproc.js
@@ -1979,7 +1979,7 @@ CSL.DateParser = function () {
 };
 CSL.Engine = function (sys, style, lang, forceLang) {
     var attrs, langspec, localexml, locale;
-    this.processor_version = "1.0.262";
+    this.processor_version = "1.0.263";
     this.csl_version = "1.0";
     this.sys = sys;
     this.sys.xml = new CSL.System.Xml.Parsing();
@@ -11383,6 +11383,7 @@ CSL.Disambiguation.prototype.disNames = function (ismax) {
         this.state.registry.registerAmbigToken(this.akey, "" + this.nonpartners[0].id, this.betterbase);
         this.lists[this.listpos] = [this.base, this.partners];
     } else if (this.clashes[1] < this.clashes[0]) {
+        this.betterbase = CSL.cloneAmbigConfig(this.base);
         this.lists[this.listpos] = [this.base, this.partners];
         this.lists.push([this.base, this.nonpartners]);
     } else {
@@ -11441,7 +11442,7 @@ CSL.Disambiguation.prototype.disYears = function () {
 };
 CSL.Disambiguation.prototype.incrementDisambig = function () {
     var val, maxed;
-    maxed = false;
+    var maxed = false;
     if ("disNames" === this.modes[this.modeindex]) {
         var increment_name = false;
         var increment_nameset = false;
@@ -11482,6 +11483,7 @@ CSL.Disambiguation.prototype.incrementDisambig = function () {
                     }
                 } else {
                     maxed = true;
+                    this.base = CSL.cloneAmbigConfig(this.betterbase);
                     if (this.modeindex < this.modes.length - 1) {
                         this.modeindex += 1;
                     }